Process for stabilizing gasoline and the like



Patented Nov. 1 1932 UNHTED STATES PATENT OFFICE GUSTAV EGLOFF, OF CHICAGO, ILLINOIS, ASSIGNOR TO UNIVERSAL OIL PRODUCTS COMPANY, OF CHICAGO, ILLINOIS, A. CORPORATION OF SOUTH DAKOTA PROCESS FOR STABILIZING GASOLINE AND THE LIKE No Drawing.

This invention relates to stabilization of gasolines, and more particularly to the prevention of color formation and gum forming substances in gasoline, and also to prevent the reduction of antiknock properties of said gasolines on storage.

It has been observed that when gasolines are stored, particularly cracked gasolines, and especially under the influence of light and oxygen, chemical changes occur which affect the color, increase the gum formation, and reduce the antiknock properties. In some cases all of these changes occur simultaneously, whilein others they occur independently or in pairs. Although the chemistry of these changes is not thoroughly understood, I have discovered that certain compounds act as stabilizing or inhibiting agents and substantially prevent this undesirable chemical change from occurring.

Generally speaking, cracked gasolinesare composed of mlxtures of hydrocarbons,

principal among which are the aromatic, unsaturated, naphthene, and paraffin hydro-.

carbons. While it has not been definitely proven, it is believed that color and gum formation and reduction in antiknock properties upon storage involve changes in the unsaturated compounds, more particularly in f: the highly unsaturated compounds such as diolefins, terpenes, and related compounds. Oxidation products ofthe various hydrocarbons present in the gasolines are apparently responsible also for the changes noted.

The formation of color in gasolines is undesirable mainly from a marketing viewpoint, for changes in color are usually accom-' panied by the formation of gum-like and polymer-like materials which affect not only the sale of the gasoline when dispensed from visible bowls, but alsofthe .operatiouof the motor'owing toclogging of the gasoline feed lines, interference with the proper operw tion of the carburetor, and the sticking of i valves in the motor. Gum formation is likewise objectionable for the same reasons.

The gum content of a gasoline is measured by a test which involves the gum formation. The present test is stated in terms of milliit is as a motor fuel.

' premium.

Application filed November 4, 1929. Serial No. 404,839.

grams of gum formed upon the evaporation of a specific volume of the gasoline, namely, 100, cc. The presence of oxygen during evaporation increases the gum formation, but as this condition is one which is present in the use of the gasoline, it has a bearing upon its performance in the motor. The socalled gum content of the gasoline will also vary as a function of the material in which it is evaporated, for example, in the presence of copper, thercsulting gum willloe very much higher than in'glass. These tests have a bearing upon the performance of the gasoline in the motor and its auxiliary feed system, and the beneficial effects of my invention Will be indicated by such tests as well as by actual motortests.

The antiknock property of a gasoline is among its most important and valuable characteristics. The higher the antiknock value sure and compression ratio, it is desirable that a motor fuel possess sufficiently high antiknock properties to avoid knocking. The

. present tendency is to increase the compression pressure of motors in order to increase thelr 'efiiciency or'mileage per gallon of fuel consumed so that antiknock fuels are at a...

The changein. antiknock rating during storage ofa motor fuel is particularly embarrassing in that although the antiknock rating of a tankof motor fuelis established and found to be satisfactory, there isa com plete uncertainty as to its antiknock value at the time of sale?" The economic loss of restor: 1

s h' eelie te e ie e tilme l value can be realized from cases which have been observed where the antiknock value has dropped from approximately fifty percent' shows a tendency to depreciate with respect to color, gum, and antiknock properties, that such gasolines will practicallymetain their 4 observed, for example with a gasoline showoriginal condition. I have found that these venting or reversing the changes which take place as aresult of storage, exposure to light, or oxidation naturally occurring or under aocelerated conditions.

I have discovered that derivatives of anthracene, such as anthrols, anthranols, anthracene hydrides, anthraquinones, when added to motor fuels, especially cracked gasoline, are capable of accomplishing the stabilizin'g and inhibiting effects above pointed out, more particularly with respect to the stabilization of color and antiknock values, and in the present invention I employ for the purposes set forth the compounds named.

Certain of the above compounds may possess antiknock properties, but the present inventlon is to be distinguished from the more addition of antiknock compounds to motor fuels in that my treatment prevents deterioration of the gasoline upon storage or removes undesirable characteristics which have formed during storage, particularly with rc spect to color and antiknock depreciation. In my invention the amount of reagent employed is materially less than that required in motor fuels to impart antiknock properties thereto.

As examples of the color stabilizing properties of derivatives of anthracene, I may cite the following:

Starting with a gasoline of 18 color, which on exposure to diffused sunlight for several days dropped to 14, I have found that by the addition of approximately 0.1% of derivatlves of anthracene that the resultant color under similar conditions of exposure is 19, actually showing an improvement in color with the stabilizer.

Similarly I have found that with certain gasolines showing a marked tendency to depreciate in antiknock value without the addition of derivatives of anthracene one can by the addition oflapproximately 0.1% of the derivatives of anthracene avoid such depreciation. As an example a cracked gasoline upon storage without the use of my reagents dropped in antiknock value to zero-benzol equivalent from a value of approximately benzol equivalent when stored for several months. Upon the addition of 0.1%

this invention are a dded'to a gasoline which inhibitors or stabilizers are effective in pre- 'prevented by the addition of small amounts of derivatives of anthracene;

Stabilization of gum formation was also ing a gum content of 15 milligrams by the copper dish test. No substantial increase in the gum formation was observed, after a long period of storage or exposure of the gasolineto which a small quantity of an anthracene derivative was added.

It can be appreciated that the present invention is of prime importance to the oil refining industry since it assures a stable product after refining, and at the same time avoids a large expenditure in bringing up the antiknock properties of depreciated gasoline by the addition of cost-1y antiknock dopes or hydrocarbons, for example benzol. These inhibitors are not to be confused with antiknock dopes because the amount added will impart practically no antiknock properties per se, but simply acts to -prevent the loss of antiknock and other desirableproperties of the gasoline.

The above examples are given by way of illustration only,and are not to be construed as limitations upon the spirit and broad scope of the invention.

I claim:

l. A process for preventing deterioration during storage of cracked gasoline having anti-knock properties which comprises addingto such gasoline from a trace up to two percent of anthraquinone.

2.. Motor fuel comprising cracked gasoline having anti-knock properties and containing from a trace up to two percent of anthraquinone. I

3. A process for preventing deterioration during storage of cracked gasoline having anti-knock properties which comprises adding to such gasoline approximately 0.1% of anthraquinone.

4. Motor fuel comprising cracked gasoline having anti-knockproperties and containing approximately 0.1% of anthraquinone.

In testimony whereof I afiix'my signature.

GUSTAV, EGLUFF. 

